Twitter Tracker

During my free time I like to take motorcycle trips and if you ever ridden a motorcycle for a long distance you will know that it can be a bit more difficult to take care of things that are normally pretty easy in the car.  With that said, I probably don’t check in with my spouse as often as I should.  Being that a motorcycle poses a higher chance of injury than a car, my wife tends to worry if she hasn’t heard from me in awhile.  To try and alleviate some of this anxiety I looked into a number of tracking systems where my wife could easily look to see where I have been.  There are numerous vendors out there using gprs and sms to update a database with your location.  Many of these are quite costly for the base unit and the actual fees for access to the database.  Being the embedded design engineer I am I knew there had to be a better way. So for about $100 for hardware and $15/month for sms’s you have the Twitter Tracker as seen below.

Alex over at Tinkerlog posted about using the Telit GM862, Twitter, and Google Maps for a mobile tracking solution. Although Alex did not link all these directly, I put the pieces of the puzzle together to see the solution you see here today.  Overall the design is complete and very professional through the use of a proper pcb and enclosure from SFE.

Overall the idea is pretty simple.  I use a pre-paid unlimited SMS plan ($15/month) through T-Mobile that allows me to send SMS messages.  By registering the mobile number of the assigned SIM card I can register this account with Twitter.  By doing so I am then able to send Google Map links right to my twitter account every 60 seconds when I am riding.  These Google Map links are done by using the gps location from the gps device on the GM862 through the use of the GPSACP command.  Parsing this string for the lat/lon locations in DDMM.MMMM format to Decimal Degrees.  Results of these actions can be seen at the twitter page for my motorcycle.

A bit of breadboarding through the use of Sparkfun’s GM862 Breakout Board and MikroE’s GM862 Smart Board made the identification of the AT protocol and design of the the 12V -> 4V power supply design much easier.  Full schematics of the design are below in .pdf format.

The code for this project was developed in the Proton Development Suite that we sell. Overall it was very easy to use and is pretty easy to program. In fact, the code can be edited and recompiled using the free Amicus 18 compiler since this design uses the 18F25K20 uProcessor.  Source code to make this project work can be found here -> Source Code.

Let me know if you are interested in purchasing a complete setup and I’ll consider offering this design for sale!

27 Responses to “Twitter Tracker”

  1. ManuelSeptember 8, 2010 at 2:04 pm #

    Definitly interested! Maybe a config-file would be great, so that you can config the upload-url?

    Oh.. and your GPS-Logger i purchased a few years ago, still works like a charm. (Power-connection broke once, but was fixed in a few minutes)

  2. WayneSeptember 8, 2010 at 2:56 pm #

    This is very impressive. I would be interesting in a completed working unit…..

  3. adminSeptember 8, 2010 at 3:06 pm #

    Wayne, its all super simple to build. I am thinking of a beta run of 10 or so. I’ll keep updates going here on the blog.

  4. adminSeptember 8, 2010 at 3:08 pm #

    Manuel, glad to hear things are still working! A more polished version would include a usb to serial chip to allow you to talk directly to the GM862. I used the MCP220 breakout board to help register the mobile phone with Twitter etc. But I agree something besides reflashing the chip is the way to go.

  5. Alex L.September 8, 2010 at 8:19 pm #

    Hey, I’m interested on buying a kit/product.

  6. adminSeptember 8, 2010 at 8:37 pm #

    Alex, I think you and a few others are interested in this. After today, I am going to start on a more complete and sellable version with a few more features.

  7. JimSeptember 8, 2010 at 10:50 pm #

    I’d be interested in this…. And I think a few other people around here would like it to keep tabs on the newly licensed teenage drivers too. E-mail me and maybe we both can make something of this…

  8. adminSeptember 8, 2010 at 11:08 pm #

    Jim, I will definitely do that. I haven’t figured it out, but you can also add other tags to the google maps links so that this all shows up pretty easily. It wouldn’t be that hard to add geofence or say, speed threshold triggered tweets, etc. The code is all open source and can be compiled with a free compiler too! So really the sky is the limit!

  9. andrewSeptember 9, 2010 at 12:42 am #

    Very interested in purchasing one of these. What would be nice accessory is a battery pack for portability.

  10. adminSeptember 9, 2010 at 12:56 am #

    Andrew, I agree having the battery makes this a much more “portable” platform in that it really opens up a lot of opportunities to do other things. Adding charge circuitry to charge off the ignition or other dc input would not be hard at all. A little vibration sensor to put it to sleep or wakeup is also pretty easy since I am doing all these things on the latest version of the gps logger.

  11. EdSeptember 9, 2010 at 6:00 am #

    Vibration sensing to activate and put the device to sleep is a great idea.
    I’d be very interested in buying a complete setup for use here in the UK, after doing the same homework as you and finding current OEM systems limited and way overpriced.
    Can you change the frequency of text updates to say one every half hour?

  12. adminSeptember 9, 2010 at 8:10 am #

    Ed, right now it’s really easy to change the updates via the code. But a 30 minute rate is definitely possible. I’d like to make it so that this was easily configurable wither through a text,computer, or even a tweet. It’ll take a little bit of work. But now tha I know people are intersted I’ll look at this more closely.

  13. artSeptember 9, 2010 at 10:49 am #

    I’d be down for one. Battery pack would be ideal — maybe a solar option, too?

  14. PeterSeptember 9, 2010 at 11:10 am #

    I have wanted to build this project for a very long time to give me piece of mind when I park my moped.

  15. KlausSeptember 21, 2010 at 7:36 am #

    Why are you using the expensive GM862GPS? By using chinese GSM modems like e.g. SIM300D, SIM340D, SIM900D and separate GPS modul it is possible to reduce over all cost by at least 50%.

  16. adminSeptember 22, 2010 at 10:01 pm #

    Klaus, good point. I had been wanting to do this project for awhile and when I purchased the GM862 these other units were not available. I might look at these in the future. Having the option to run the GM862 using python was another option that I was considering, but opted for the seperate microcontroller.

  17. JameeSeptember 28, 2010 at 11:53 am #

    I would love to get one, this is exactly what I was looking for.

  18. LySeptember 29, 2010 at 8:32 pm #

    I’m very impressed by your piece of work!
    I’m actually a Senior EE student and was thinking of incorporating a GPS tracker into a smart car alam system.
    Pretty much when the car get stolen I can get an SMS on my phone of the location where my car is at the moment.
    So I was browsing online and found your article. Do you mind giving me more insight?
    Thank you, and again good work!

  19. LeeSeptember 29, 2010 at 8:39 pm #

    I’m very impressed by the work you did! it looks very simple and powerfull.
    I’m actually a Senior EE student, and was thinking of implementing a GPS tracker in my senior project (It’s a smart car alarm system).
    I looked at the schematic and it looks pretty simple. Do you think you can give me some insight on how what first few steps I should take to approach such a similar project?
    ps: I’ve attached my email address.
    And again Very impressive

  20. BobOctober 14, 2010 at 11:37 am #

    So how do I buy one?

  21. tsankoOctober 18, 2010 at 10:18 am #

    Wonderful ..thanks a lot for posting a good informitive blog

  22. ryan recceOctober 20, 2010 at 9:14 am #

    I would be interested in purchasing one of these units. Please email me. Thanks, Ryan

  23. JDGNovember 13, 2010 at 1:56 am #

    So, I’m in N.D. No AT&T, No T-Mobile, just Verizon. Yet, there’s GSM coverage up here. ?What? I’m not ‘technology’ challenged at all. I build stuff with PICs/Atmel all the time, but I haven’t had a need for SMS until now, so I’m not 100% sure on how SMS works (other than basically piggybacking onto the handshaking signals which is the main reason for the 140/161 character limit).
    In theory, I should be able to go to T-Mobile’s website and order the $7 “T-Mobile Prepaid SIM Card Activation Kit”, along with the $15/month “Unlimited Text w/ 10 cents/min Talk”…along with the ‘862 and a handful of other parts and build something…. Even though I live in an area that’s not exclusively served by a GSM provider.
    I guess the main problem is, how do I send “texts” to an email address?

  24. DeFixNovember 29, 2010 at 10:13 am #

    I want to buy it, how much does this gonna cost me?

  25. Paul MastinDecember 12, 2010 at 11:47 am #


    Interested in this, any detailed plans that you would be willing to sell?



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